A conventional stoplight for a vehicle is disclosed in Japanese Patent Laid-open Publication No. 4 (1992)-325333. The vehicle stoplight disclosed in this document includes a lamp and a plurality of optical fibers which are independent of each other. Each of the optical fibers includes a core and a cladding which covers the core. The cladding has a refractive index which is smaller than that of the core.
The above conventional stoplight for a vehicle suffers from the disadvantage that it is costly to manufacture since each of the cores must be covered with the cladding. Also, the manufacturing process is somewhat time-consuming and lacks simplicity in structure.